KOT ADDU, Pakistan — Floodwaters that devastated Pakistan's mountainous northwest surged into the heartland today, submerging dozens of villages along bloated rivers whose torrents have killed at least 1,500 people and put 100,000 at risk of disease.

Fresh rains in the hardest-hit northwest threatened to overwhelm a major dam and unleash a new deluge.

Relief efforts for some 3.2 million people have been delayed by swamped roads, washed-out bridges and downed communication lines, and survivors have complained about government inaction.

Countries including the U.S. have pledged assistance to Pakistan, which is already struggling to control a rapacious Taliban militant movement.

BAGHDAD — Suspected al-Qaida militants killed five Iraqi soldiers in a brazen dawn attack today at a western Baghdad checkpoint and planted the terror group's black banner before fleeing the scene, officials said.It was the second time in a week that al-Qaida's flag has appeared at the scene of an attack.On Thursday, in Baghdad's Sunni Azamiyah district — a former al-Qaida stronghold — suspected al-Qaida militants stormed a checkpoint, killed 16 members of the security forces and briefly planted their banner nearby before fleeing.

KABUL, Afghanistan — Six Afghan private security guards were beheaded during a bank robbery in northern Afghanistan, police said today.Meanwhile, insurgents launched a ground attack on NATO's largest base in the south, but did not breach its defenses, officials said.It appeared that the security guards were poisoned before they were beheaded, said Sherjan Durani, a police spokesman for Balkh province. He said someone apparently mixed a poison into the guards' food Monday night.